Prescaler, Watchdog, (Cycle-) Timer

src/main/java/fabrik/simulator/pic16f84/PreScaler.java

@@ -0,0 +1,43 @@
+package fabrik.simulator.pic16f84;
+
+public class PreScaler {
+    private static final int PSA = 0x3;
+    private static final int OPTION = 0x81;
+
+    private static int scaler = 0b111;
+
+    public static boolean isPrescalerOnTimer (){
+        return DataRegister.getDirectBit(OPTION, PSA) == 0;
+    }
+
+    public static int getFactor () {
+        int scale = DataRegister.getDirectRegister(OPTION) & 0b111;
+        int timer = isPrescalerOnTimer() ? 1 : 0;
+        return (int) Math.pow (2, scale+timer);
+    }
+
+    public static void reset (){
+        DataRegister.setDirectBit(OPTION, 0, 0);
+        DataRegister.setDirectBit(OPTION, 1, 0);
+        DataRegister.setDirectBit(OPTION, 2, 0);
+    }
+
+    public static void resetFromRegister() {
+        scaler = getFactor();
+    }
+
+    public static void decrement() {
+        scaler--;
+        if (scaler == 0) {
+            scaler = getFactor();
+            Timer.incrementFromInstructionCycle();
+        }
+        System.err.println("VT: " + scaler);
+    }
+
+    public static void cycles(int i) {
+        for (int j = 0; j < i; j++) {
+            decrement();
+        }
+    }
+}